There is a 'Share' button to the upper-right of your greenfoot application frame. Click on it and make sure you are on the 'Publish' tab. Enter the required info, adjust your screenshot (image icon for the scenario), ensure the checkboxes are set for what you want, enter your on-site login password and click 'Share'.

You do have a member page -- and any scenarios you upload will be accessible through it. This is your page: http://www.greenfoot.org/users/24176.